Question

36.
The number of moles present in 90 g of water is ....
(A) 0.5
(B) 5
(C) 5.5
(D) 50​

Answer 1

Molar mass of H20 = 2×1 + 16

==> molar mass = 18 g

Given mass = 90 g

So,

num. of mole = given mass / molar mass

==> 90 / 18

==> 5

5 mole of H20 is present in 90 g of water.

Hence, Option B is correct.